Circuit arrangements for smoothing alpha direct current ripple



p 6, 1932- H. VAN SUCHTELEN 1,875,961

CIRCUIT ARRANGEMENTS FOR SMOOTHING A DIRECT CURRENT RIPPLE Filed Aug. 23, 1950 INVENTOR HAROLD VAN SUCHTELEN ATTORNEY Patented Sept. 6, 1932 UNITED STATES PORATION or AMERICA, A CORPORATION or DELAWARE.

CIRCUIT ARRANGEMENTS FOR SMOOTHING A IDIRECTCURRENT BIPILE Application filed August 23, 1930, Serial No. 477,284, and in the Netherlands August-24, 1929.

As is well known, the current supplied by commercial direct-current systems always has a ripple superposed on the pure direct current, said ripple being substantially due to the commutation phenomena of the directcurrent dynamo (the so-called collector ripp For some purposes, for example for feed ing the anode circuits of wireless receiving sets, this ripple must be made harmless in some way or other. Use is commonly made for this purpose of one or more choke coils connected in series with the leads and of one or more parallel condensers across the said leads. However, this is not always sutficient as a portion of the collector ripple may be left, viz. the portion relatively to earth. In fact, one of the two leads is mostly earthed so that in this case it is desirable or neces sary to provide a smoothing condenser between the other lead and the earth.

According to the invention, in addition to one or more choke coils and one or more parallel condensers across the leads, there is provided a special condenser which has one of its armatures connected to earth whereas with the aid of a change-over switch the other armature may be connected at will to either of the said two leads.

In fact, it cannot always be directly determined which of the two leads (the plus or the minus lead) is earthed at the central gen erating station. Owing to the arrangement according to the invention, a simple shifting of the switch suffices to find this out as in the correct position the ripple entirely disappears or at any rate becomesleast audible.

The invention will be described more fully with reference to the accompanying diagram which illustrates, by way of example, an embodiment of the invention.

In this diagram 1 and 2 denote the two contacts of a wall contact, said contacts being connected to the plus and minus lead respectively. The plus lead is further assumed to be earthed at the central generating station.

The apparatus for smoothing out the ripple, a so-called high-tension supply unit, is provided with a plug the two contacts 3 and 4 ot'which are connected totthe network con-- tacts l and 2 respectively. In the two leads coming from the contacts 3 and 4t are inserted PATENT oFi icEI HAROLD VAN SUCH'IELEN, or EINDHOVEN, NETI-iERLANDS, Assrenon TO RADIO conchoke coilwindings 5 and 6 respectively which;

are wound arounda common iron core 7. The

other ends of the coils 5 and 6 are connected to one another by. a parallel'condenser 8 and further to contacts 18 and 14 respectively to which the receiving set or other consuming apparatus may be connected.

The so-called ripple between the terminal points of the windings 5 and 6 is considerably reduced by the coils 5 and 6 and the condenser 8. However, neither of these two ends is connected to earth so that they may still show a small ripple with relation to earth.

This applies more particularly to the end of the coil included in the lead which is not earthed, in thepresent case consequently to the right hand end of the coil 6. This end is connected to the contact 10 of a change-over switch 11 the switch arm of which is connected to earth via a condenser 12. In the other position of the switchll said arm rests on a contact 9 which is connected to the right hand end of the coil 5. The switch is brought into this position if the lead in which the coil 6 is inserted, is connected to earth.

I claim: a

1. In combination with a source of pulsating direct current a circuit including a positive lead and a negative lead connected to said source one of said leads being grounded, a filter arrangement comprising a pair of choke coils wound about the same core connected respectively to said two leads, a condenser shunted across, said two leads, an auxiliary condenser having one side thereof grounded and means including a switching arrangement for connecting the other side of said auxiliary condenser to either one of said denser, means for grounding one side of said auxiliary'condenser and means for connecting the other side of said auxiliary condenser to either one of said output terminals said last named means comprising a selectiveswitching device;

3. In combination, a source of pulsating direct current including a positive lead and a negative lead one of said leads being grounded,. a pair of output terminals, means in- V eluding a choke coil for connecting one of said leads to one of said output terminals,

means including a second choke coil for connecting the other output terminal to the other lead, an iron core about which both of'said choke coils are wound, a capacityrconnected between said two output terminals, an auxiliary capacity and means including a selective switching arrangement for connecting either one of said output terminals to ground through said auxiliary capacity.

HAROLD VAN SUCHTELEN. 

